Cell Biology: Intracellular Trafficking 129a. It is the inactive cAMP kinase
b. It lacks GTPase activity
c. It inactivates adenylate cyclase
d. It is bound to GTP in the inactive state
e. It is the stimulatory G protein (GS)
(Modified, with permission, from Avery JK:Oral Development and Histology,3/e.
New York:Thieme Medical, 2001).